In the related art, a switched capacitor circuit including an operational amplifier is known as an amplifier circuit that amplifies an analog signal with a predetermined gain. According to such a switched capacitor circuit, a virtual ground voltage more closely approaches an ideal value and the amplification precision is further enhanced as the gain of the operational amplifier increases. However, as CMOS type devices have decreased further in size in recent years, it becomes more difficult to design an operational amplifier with a high gain while still meeting target device sizes. The amplifier circuit in the related art thus has a problem that an amplification error increases with decreased device sizes.
A switched capacitor circuit including a comparator instead of the operational amplifier has also been proposed. However, the switched capacitor circuit in this instance causes an amplification error in accordance with a finite delay in the comparator.